Amorphization-Driven Lithium Ion Storage Mechanism Change for Anomalous Capacity Enhancement.

Capacity fading as a function of lithiation/delithiation cycles is a major limitation of Li-ion batteries. Most Li storage materials are susceptible to this phenomenon due to the degradation of the crystal structure and particle integrity as a result of volume changes associated with lithiation/delithiation processes and/or irreversible redox reactions. However, some Li storage materials show an increase in capacity with an increase in cycles; this phenomenon has been termed "negative fading.

Carbon-Doped TiNbO Suppresses Amorphization-Induced Capacity Fading.

The limited capacity of graphite anodes in high-performance batteries has led to considerable interest in alternative materials in recent years. Due to its high capacity, titanium niobium oxide (TiNbO, TNO) with a Wadsley-Roth crystallographic sheared structure holds great promise as a next-generation anode material, but a comprehensive understanding of TNO's electrochemical behavior is lacking. In particular, the mechanism responsible for the capacity fading of TNO remains poorly elucidated.

Nanostructuring Matters: Stabilization of Electrocatalytic Oxygen Evolution Reaction Activity of ZnCoO by Zinc Leaching.

Despite the enormous attention paid to cobalt oxide materials as efficient water splitting electrocatalysts, a deep understanding of their activity discrepancy is still elusive. In this work, we showed that stabilization of the internally generated oxygen evolution reaction (OER) active phase (oxyhydroxide) is crucial for ZnCoO electrocatalysts. A systematic evaluation of the bulk and nanostructured ZnCoO system concomitant with nanostructured CoO showed that leaching of Zn is the driving force behind the near-surface transformation to the oxyhydroxide phase.